Method and configuration for coding a digitized picture, and method and configuration for decoding a digitized picture

ABSTRACT

Pixels in a digitized picture are grouped into picture blocks, which in turn are grouped at least in a first picture region and a second picture region. An overall motion vector is determined, through the use of which any shifting of the first picture region in comparison to the first picture region in a previous picture is described. The overall motion vector is allocated to all the picture blocks in the second picture region. A motion vector is determined for each of the picture blocks in the first picture region. The coding information of the picture blocks, the motion vectors and the overall motion vector are coded. A configuration for coding a digitized picture and a configuration for decoding a compressed picture are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application is a continuation of copending InternationalApplication No. PCT/DE99/01964, filed Jul. 1, 1999, which designated theUnited States.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The invention relates to a method and a configuration for codinga digitized picture, and to a method and a configuration for decoding adigitized picture.

[0004] A block-based picture coding method is described in the ITU-TDraft Recommendation H.263, Video Coding for Low Bitrate Communication,May 1996. In this picture coding method, a picture to be coded haspixels to which coding information is allocated.

[0005] In the following text, the term coding information meansluminance information (brightness information) or chrominanceinformation (color information).

[0006] The pixels are grouped to form picture blocks, which normallycontain 8×8 pixels or 16×16 pixels. The picture blocks are grouped toform macroblocks. A macroblock has four picture blocks with luminanceinformation, and two picture blocks with chrominance information.

[0007] A so-called hybrid picture coding method is used for coding inthe method described in the ITU-T Draft Recommendation H.263, VideoCoding for Low Bitrate Communication, May 1996. This means a method inwhich, firstly, a discrete cosine transformation is carried out for thepicture blocks and only spectral coefficients are transmitted while,secondly, attempts are made to avoid transmitting redundant information,contained in successive digitized pictures.

[0008] The term redundant information broadly defines coding informationwhich has already been transmitted in a previous picture.

[0009] Movement information or shift information is transmitted in thiscontext. This means that a determination is made of how a picture blockhas moved or shifted in its position within the picture from a previouspicture to the picture to be coded. This movement or shift is determinedand coded in the form of a vector, the motion vector, for each pictureblock to be coded. This method is referred to as motion estimation.

SUMMARY OF THE INVENTION

[0010] It is accordingly an object of the invention to provide a methodand a configuration for coding and for decoding a digitized picture inwhich the required digital information for describing the digitizedpicture is less than that for known methods, without detractingsignificantly from the subjective quality impression of thereconstructed picture.

[0011] With the foregoing and other objects in view there is provided,in accordance with the invention, a method for coding a digitizedpicture, including the steps of:

[0012] providing a digitized picture having pixels and providing codinginformation allocated to the pixels;

[0013] grouping the pixels into picture blocks;

[0014] grouping the picture blocks to form at least a first pictureregion and a second picture region;

[0015] determining an overall motion vector, the overall motion vectordescribing a shift of the first picture region in comparison to thefirst picture region in a previous predecessor picture and/or the firstpicture region in a subsequent successor picture;

[0016] allocating the overall motion vector to at least some of thepicture blocks in the second picture region;

[0017] determining respective motion vectors for the picture blocks inthe first picture region and allocating the respective motion vectors tothe picture blocks in the first picture region; and

[0018] coding the coding information of the picture blocks, the motionvectors and the overall motion vector.

[0019] In other words, in the method for coding a digitized picture withpixels to which coding information is allocated, the pixels are groupedinto picture blocks. The picture blocks are grouped to form at least afirst region and a second region. An overall motion vector is determinedthrough the use of which any movement or shift of the first region incomparison to the first region in a previous predecessor picture and/orin comparison to the first region in a subsequent successor picture isdescribed. The overall motion vector is allocated to at least some ofthe picture blocks in the second picture region. A motion vector isdetermined and is allocated to the picture block for each picture blockin the first picture region. Coding information for the picture blocksis coded, as are the motion vectors and the overall motion vectors.

[0020] With the objects of the invention in view there is also provided,a method for decoding a compressed picture, which includes the steps of:

[0021] providing a compressed picture having pixels and providing codinginformation allocated to the pixels, the pixels being grouped intopicture blocks, the picture blocks being grouped into at least a firstpicture region and a second picture region, the picture blocks, motionvectors of the picture blocks in the first picture region and an overallmotion vector being coded, the overall motion vector being used todescribe a shift of the first picture region in comparison to the firstpicture region in a previous predecessor picture and/or the firstpicture region in a subsequent successor picture; and

[0022] carrying out a decoding of the compressed picture by using theoverall motion vector for decoding at least some of the picture blocksin the second picture region.

[0023] In other words, in the method for decoding a compressed picturewith pixels to which coding information is allocated, the pixels aregrouped into picture blocks. The picture blocks are grouped into atleast a first picture region and a second picture region. The pictureblocks, motion vectors for picture blocks in the first region and anoverall motion vector are coded. The overall motion vector is used todescribe any movement (shift) of the first picture region in comparisonto the first picture region in a previous predecessor picture and/or incomparison to the first picture region in a subsequent successorpicture. The decoding is carried out in such a manner that the overallmotion vector is used for decoding at least some of the picture blocksin the second picture region.

[0024] According to another mode of the invention, the overall motionvector is determined from motion vectors of picture blocks in the firstpicture region.

[0025] According to yet another mode of the invention, the overallmotion vector is determined by forming a mean value of motion vectors ofpicture blocks in the first picture region.

[0026] According to yet further mode of the invention, the overallmotion vector is determined from motion vectors of given picture blocksin the first picture region, the given picture blocks being locatedsubstantially at an edge of the first picture region.

[0027] With the objects of the invention in view there is furtherprovided a configuration for coding a digitized picture, including:

[0028] a processor configured to process a digitized picture havingpixels and coding information allocated to the pixels;

[0029] the processor grouping the pixels into picture blocks;

[0030] the processor grouping the picture blocks to form at least afirst picture region and a second picture region;

[0031] the processor determining an overall motion vector, the overallmotion vector describing a shift of the first picture region incomparison to the first picture region in a previous predecessor pictureand/or the first picture region in a subsequent successor picture;

[0032] the processor allocating the overall motion vector to at leastsome of the picture blocks in the second picture region;

[0033] the processor determining respective motion vectors for thepicture blocks in the first picture region and allocating the respectivemotion vectors to the picture blocks in the first picture region; and

[0034] the processor coding the coding information of the pictureblocks, the motion vectors and the overall motion vector.

[0035] In other words, the configuration for coding a digitized picturewith pixels to which coding information is allocated has a processorwhich is set up such that the following steps can be carried out:

[0036] the pixels are grouped into picture blocks,

[0037] the picture blocks are grouped at least in a first picture regionand a second picture region,

[0038] an overall motion vector is determined, through the use of whichany movement of the first picture region in comparison to the firstpicture region in a previous predecessor picture and/or in comparison tothe first picture region in a subsequent successor picture is described,

[0039] the overall motion vector is allocated to at least some of thepicture blocks in the second picture region,

[0040] a motion vector is determined and is allocated to the pictureblock for each picture block in the first picture region, and

[0041] the coding information of the picture blocks is coded, as are themotion vectors and the overall motion vector.

[0042] With the objects of the invention in view there is also provided,a configuration for decoding a compressed picture, including:

[0043] a processor configured to process a compressed picture havingpixels and coding information allocated to the pixels, the pixels beinggrouped into picture blocks, the picture blocks being grouped into atleast a first picture region and a second picture region, the pictureblocks, motion vectors of the picture blocks in the first picture regionand an overall motion vector being coded, the overall motion vectorbeing used to describe a shift of the first picture region in comparisonto the first picture region in a previous predecessor picture and/or thefirst picture region in a subsequent successor picture; and

[0044] the processor carrying out a decoding of the compressed pictureby using the overall motion vector for decoding at least some of thepicture blocks in the second picture region.

[0045] In other words, the configuration for decoding a compressedpicture with pixels to which coding information is allocated has aprocessor which is set up such that the following steps can be carriedout:

[0046] the pixels are grouped into picture blocks,

[0047] the picture blocks are grouped into at least a first pictureregion and a second picture region,

[0048] the picture blocks, motion vectors of picture blocks in the firstpicture region and an overall motion vector are coded,

[0049] the overall motion vector is used to describe any movement(shift) of the first picture region in comparison to the first pictureregion in a previous predecessor picture and/or in comparison to thefirst picture region in a subsequent successor picture,

[0050] the decoding is carried out in such a manner that the overallmotion vector is used for decoding at least some of the picture blocksin the second picture region.

[0051] The invention results in a reduction in the required data ratefor transmission of digitized pictures, or allows the overall availabledata rate to be utilized better, and this can be used to improve thepicture quality.

[0052] According to another feature of the invention, the processor isconfigured to determine the overall motion vector from motion vectors ofpicture blocks in the first picture region.

[0053] According to a further feature of the invention, the processor isconfigured to determine the overall motion vector by forming a meanvalue of motion vectors of picture blocks in the first picture region.

[0054] According to another feature of the invention, the processor isconfigured to determine the overall motion vector from motion vectors ofgiven picture blocks in the first picture region, the given pictureblocks being located substantially at an edge of the first pictureregion.

[0055] It is advantageous to determine the overall motion vector frommotion vectors of picture blocks in the first picture region, becausethe overall motion vector in this way more accurately describes themovement of the first picture region, which means that the quality ofthe decoded and reconstructed picture is improved.

[0056] A further improvement is obtained if the overall motion vector isdetermined from motion vectors from picture blocks in the first pictureregion which are located essentially at an edge of the first pictureregion.

[0057] Other features which are considered as characteristic for theinvention are set forth in the appended claims.

[0058] Although the invention is illustrated and described herein asembodied in a method and configuration for coding a digitized picture,and a method and configuration for decoding a digitized picture, it isnevertheless not intended to be limited to the details shown, sincevarious modifications and structural changes may be made therein withoutdeparting from the spirit of the invention and within the scope andrange of equivalents of the claims.

[0059] The construction and method of operation of the invention,however, together with additional objects and advantages thereof will bebest understood from the following description of specific embodimentswhen read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0060]FIG. 1 is a sketch illustrating the principle on which theinvention is based;

[0061]FIG. 2 is a block diagram of a configuration with two computers, acamera, and a screen, through the use of which the picture data arecoded, transmitted, decoded and displayed;

[0062]FIG. 3 is a block diagram of an apparatus for a block-based codingof a digitized picture; and

[0063]FIG. 4 is a flowchart illustrating the method steps for coding,transmission and decoding of a digitized picture.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0064] Referring now to the figures of the drawings in detail and first,particularly, to FIG. 2 thereof, there is shown a configuration whichincludes two computers 202, 208 and a camera 201. FIG. 2 illustrates thepicture coding, the transmission of picture data and the picturedecoding.

[0065] A camera 201 is connected to a first computer 202 via a line 219.The camera 210 transmits recorded pictures 204 to the first computer202. The first computer 202 has a first processor 203, which isconnected via a bus 218 to a frame storage 205. A method for picturecoding is carried out using the first processor 203 in the firstcomputer 202. Picture data 206 coded in this way are transmitted fromthe first computer 202 via a communication link 207, preferably a lineor a radio link, to a second computer 208. The second computer 208contains a second processor 209, which is connected via a bus 210 to aframe storage 211. A method for picture decoding is carried out usingthe second processor 209.

[0066] Both the first computer 202 and the second computer 208 have arespective screen 212 and 213, on which the picture data 204 aredisplayed, with the display on the screen 212 of the first computer 202normally being only for monitoring purposes. Input units, preferably akeyboard 214 or 215, respectively, and a computer mouse 216 or 217,respectively, are in each case provided to control both the firstcomputer 202 and the second computer 208.

[0067] The picture data 204 which are transmitted from the camera 201via the line 219 to the first computer 202 are data in the time domain,while the data 206 which are transmitted from the first computer 202 tothe second computer 208 via the communication link 207 are picture datain the spectral domain. The decoded picture data are displayed on thescreen 213.

[0068]FIG. 3 shows a schematic configuration for carrying out ablock-based picture coding method in accordance with the H.263 Standard.

[0069] A video data stream to be coded and with successive digitizedpictures is supplied to a picture coding unit 301. The digitizedpictures are subdivided into macroblocks 302, with each macroblockcontaining 16×16 pixels. The macroblock 302 includes 4 picture blocks303, 304, 305 and 306, with each picture block containing 8×8 pixels towhich luminance values (brightness values) are allocated. Furthermore,each macroblock 302 includes two chrominance blocks 307 and 308 withchrominance values (color information, color saturation) allocated tothe pixels.

[0070] The block for a picture contains a luminance value (=brightness),a first chrominance value (=hue) and a second chrominance value (=colorsaturation). In this case, the luminance value, first chrominance valueand second chrominance value are referred to as color values.

[0071] The picture blocks are supplied to a transformation coding unit309. In the case of difference-picture coding, values to be coded forpicture blocks in previous pictures are removed (subtracted) from thepicture blocks to be coded at that time, and only the difference-forminginformation 310 is supplied to the transformation coding unit (discretecosine transformation DCT) 309. For this purpose, the current macroblock302 is reported via a link 334 to a motion estimation unit 329. Spectralcoefficients 311 are formed in the transformation coding unit 309 forthe picture blocks or difference picture blocks to be coded, and aresupplied to a quantization unit 312.

[0072] Quantized spectral coefficients 313 are supplied in a backwardpath both to a scanning unit 314 and to an inverse quantization unit315. Using a scanning method, for example a “zigzag” scanning method,entropy coding is carried out on the scanned spectral coefficients 332,in an entropy coding unit 316 provided for this purpose. Theentropy-coded spectral coefficients are transmitted to a decoder ascoded picture data 317 via a channel, preferably a line or a radio link.

[0073] Inverse quantization of the quantized spectral coefficients 313is carried out in the inverse quantization unit 315. Spectralcoefficients 318 obtained in this way are supplied to an inversetransformation coding unit 319 (inverse discrete cosine transformationIDCT). Reconstructed coding values (and difference coding values) 320are supplied in the difference picture mode to an adder 321. The adder321 furthermore receives coding values for a picture block, which resultfrom a previous picture once motion compensation has already beencarried out. The adder 321 is used to form reconstructed picture blocks322, which are stored in a frame storage 323. A clip unit 333 isprovided between the adder 321 and the frame storage 323.

[0074] Chrominance values 324 for the reconstructed picture blocks 322are supplied from the frame storage 323 to a motion compensation unit325. For brightness values 326, interpolation is carried out in aninterpolation unit 327 provided for this purpose. The interpolation ispreferably used to quadruple the number of brightness values containedin the respective picture block. All the brightness values 328 aresupplied both to the motion compensation unit 325 and to the motionestimation unit 329. The motion estimation unit 329 also receives thepicture blocks of the respective macroblock (16×16 pixels) to be coded,via the link 334. The motion estimation is carried out in the motionestimation unit 329, taking account of the interpolated brightnessvalues (“motion estimation on a half-pixel basis”).

[0075] The result of the motion estimation is a motion vector 330 whichdescribes the physical movement of the selected macroblock from theprevious picture to the macroblock 302 to be coded.

[0076] Both brightness information and chrominance information relatedto the macroblock determined by the motion estimation unit 329 areshifted through the motion vector 330 and are subtracted from the codingvalues of the macroblock 302 (see the data path 331).

[0077] The motion estimation thus results in the motion vector 330 withtwo motion vector components, a first motion vector component BV_(x) anda second motion vector component BV_(y) along the first direction x andthe second direction y: $\begin{matrix}{{BV} = \begin{pmatrix}{BV}_{x} \\{BV}_{y}\end{pmatrix}} & (1)\end{matrix}$

[0078] The motion vector 330 is allocated to the picture block.

[0079] The picture coding unit shown in FIG. 3 thus supplies a motionvector 330 for all the picture blocks and macro picture blocks.

[0080]FIG. 1 shows the principle on which the invention is based.

[0081] A digitized picture 101 has pixels 102 which are grouped intopicture blocks 103. The picture blocks are grouped into a first pictureregion 104 and a second picture region 105.

[0082] The first picture region 104 represents a highly mobile pictureforeground. The second picture region 105 represents a picturebackground which varies only to a relatively minor extent betweendirectly successive pictures.

[0083] Motion estimation is carried out for each picture block 106 inthe first picture region 104, and a motion vector 107 is determined foreach picture block 106 in the first picture region 104.

[0084] The motion estimation is carried out in such a way that thefollowing error E is determined on the basis of a starting region whosesize and shape are the same as those of the first picture block, in eachcase shifted through one pixel interval or through a fraction or amultiple of one pixel interval, preferably through half a pixel interval(half-pixel motion estimation), through which the starting region is ineach case moved: $\begin{matrix}{E = {\sum\limits_{i = 1}^{n}\quad {\sum\limits_{j = 1}^{m}\quad {{x_{i,j} - y_{i,j}}}}}} & (2)\end{matrix}$

[0085] where

[0086] i, j are sequential indices,

[0087] n is the number of pixels in the first picture block along afirst direction,

[0088] m is the number of pixels in the first picture block along asecond direction,

[0089] x_(i,j) is the coding information for the pixel at the positioni, j within the first picture block,

[0090] Y_(i,j) is the coding information for the pixel at thecorresponding point in the previous picture, shifted through thecorresponding motion vector.

[0091] The error E is calculated for each movement in the previouspicture and the picture block whose error E has the lowest value forthat movement (=motion vector) is selected as that being the mostsimilar to the first picture block.

[0092] An overall motion vector 108 is determined from the motionvectors 107 which are allocated to the picture block 106 in the firstpicture region 104.

[0093] The motion vectors for picture blocks 106 in the first pictureregion 104 and which are essentially located at the edge of the firstpicture region 104 are advantageously taken into account for thispurpose.

[0094] The overall motion vector 108 is formed by averaging the motionvectors considered.

[0095] The overall motion vector 108 describes the movement of theoverall first picture region 104 between two successive pictures.

[0096] The overall motion vector 108 is allocated to all the pictureblocks in the second picture region for coding and decoding, that is tosay the overall motion vector 108 is used as a standard motion vectorfor the second picture region 105, that is to say the picturebackground.

[0097] As can be seen, the second picture region 105, that is to say thepicture background, is thus moved as an entity. Errors occur only at thepicture edges where, however, they are perceived only to a minor extent.

[0098] It is assumed that the picture blocks in the second pictureregion have already been coded with adequate quality.

[0099] For this purpose, a quality measure is determined for each newcoded picture block by comparison with the previous picture block, onceagain by forming the sum of absolute differences via the codinginformation for the individual pixels.

[0100] The method described above is carried out in the motionestimation unit 329.

[0101] Thus, only the motion vectors 107 in the picture blocks in thefirst picture region together with the overall motion vector 108 arecoded and transmitted.

[0102]FIG. 4 shows a flowchart illustrating the individual method stepsin the exemplary embodiment once again.

[0103] In a first step (step 401), motion estimation is carried out foreach picture block in the first picture region, as a result of which amotion vector is determined for each picture block in the first pictureregion.

[0104] In a second step, an overall motion vector is determined from atleast some of the motion vectors for the picture blocks in the firstpicture region (step 402).

[0105] The coding information, the motion vectors 107 for the pictureblocks 106 in the first picture region 104, and the overall motionvector 108 are coded (step 403).

[0106] The coding information, the overall motion vector and the motionvectors for the picture blocks in the first picture region aretransmitted in a further step (step 404).

[0107] After reception of the coded picture data (step 405), the codinginformation, the motion vectors 107 for the picture blocks 106 in thefirst picture region 104 and the overall motion vector 108 are decoded,and the picture 101 is reconstructed (step 406).

[0108] The overall motion vector 108 is used for all the picture blocks109 in the second picture region 105 for reconstruction of the picture101.

[0109] This thus avoids the coding, transmission and/or storage ofmotion vectors for picture blocks in the second picture region, and thisleads to a considerable saving in the required data rate.

[0110] Alternatives to the exemplary embodiment described above areexplained below:

[0111] The nature of the motion estimation process is not relevant tothe invention, that is to say any desired method may be used for motionestimation.

[0112] The formation of the overall motion vector from the motionvectors in the first picture region is not essential to the inventioneither, that is to say averaging, weighted averaging or else only amotion vector which is regarded as being representative of all themotion vectors for the picture blocks in the first picture region can beused as the overall motion vector.

[0113] Picture information which is lacking at the picture edges as aresult of the method can be re-formed during the transmission ofsubsequent pictures with relatively little motion, or else can be readfrom a background storage, in which the corresponding pictureinformation from previous pictures is stored.

[0114] Furthermore, the invention is not limited to two picture regions.There may be a number of picture regions to which picture blocks areallocated, for example a number of independent objects which form amoving foreground. In this case, one picture object is selected forwhich an overall motion vector is then determined. The picture regionwhich describes the background is then shifted with this overall motionvector.

[0115] According to the exemplary embodiment, the error E is formed fromthe sum of the absolute differences. However, the error E can also beformed from the sum of quadratic differences or from the sum ofdifferences of higher powers. This applies in a corresponding manner tothe formation of the quality measure.

We claim:
 1. A method for coding a digitized picture, the method whichcomprises: providing a digitized picture having pixels and providingcoding information allocated to the pixels; grouping the pixels intopicture blocks; grouping the picture blocks to form at least a firstpicture region and a second picture region; determining an overallmotion vector, the overall motion vector describing a shift of the firstpicture region in comparison to at least one of the first picture regionin a previous predecessor picture and the first picture region in asubsequent successor picture; allocating the overall motion vector to atleast some of the picture blocks in the second picture region;determining respective motion vectors for the picture blocks in thefirst picture region and allocating the respective motion vectors to thepicture blocks in the first picture region; and coding the codinginformation of the picture blocks, the motion vectors and the overallmotion vector.
 2. The method according to claim 1, which comprisesdetermining the overall motion vector from motion vectors of pictureblocks in the first picture region.
 3. The method according to claim 1,which comprises determining the overall motion vector by forming a meanvalue of motion vectors of picture blocks in the first picture region.4. The method according to claim 1, which comprises determining theoverall motion vector from motion vectors of given picture blocks in thefirst picture region, the given picture blocks being locatedsubstantially at an edge of the first picture region.
 5. A method fordecoding a compressed picture, the method which comprises: providing acompressed picture having pixels and providing coding informationallocated to the pixels, the pixels being grouped into picture blocks,the picture blocks being grouped into at least a first picture regionand a second picture region, the picture blocks, motion vectors of thepicture blocks in the first picture region and an overall motion vectorbeing coded, the overall motion vector being used to describe a shift ofthe first picture region in comparison to the first picture region in atleast one of a previous predecessor picture and a subsequent successorpicture; and carrying out a decoding of the compressed picture by usingthe overall motion vector for decoding at least some of the pictureblocks in the second picture region.
 6. The method according to claim 5,which comprises determining the overall motion vector from motionvectors of picture blocks in the first picture region.
 7. The methodaccording to claim 5, which comprises determining the overall motionvector by forming a mean value of motion vectors of picture blocks inthe first picture region.
 8. The method according to claim 5, whichcomprises determining the overall motion vector from motion vectors ofgiven picture blocks in the first picture region, the given pictureblocks being located substantially at an edge of the first pictureregion.
 9. A configuration for coding a digitized picture, comprising: aprocessor configured to process a digitized picture having pixels andcoding information allocated to the pixels; said processor grouping thepixels into picture blocks; said processor grouping the picture blocksto form at least a first picture region and a second picture region;said processor determining an overall motion vector, the overall motionvector describing a shift of the first picture region in comparison toat least one of the first picture region in a previous predecessorpicture and the first picture region in a subsequent successor picture;said processor allocating the overall motion vector to at least some ofthe picture blocks in the second picture region; said processordetermining respective motion vectors for the picture blocks in thefirst picture region and allocating the respective motion vectors to thepicture blocks in the first picture region; and said processor codingthe coding information of the picture blocks, the motion vectors and theoverall motion vector.
 10. The configuration according to claim 9,wherein said processor determines the overall motion vector from motionvectors of picture blocks in the first picture region.
 11. Theconfiguration according to claim 9, wherein said processor determinesthe overall motion vector by forming a mean value of motion vectors ofpicture blocks in the first picture region.
 12. The configurationaccording to claim 9, wherein said processor determines the overallmotion vector from motion vectors of given picture blocks in the firstpicture region, the given picture blocks being located substantially atan edge of the first picture region.
 13. A configuration for decoding acompressed picture, comprising: a processor configured to process acompressed picture having pixels and coding information allocated to thepixels, the pixels being grouped into picture blocks, the picture blocksbeing grouped into at least a first picture region and a second pictureregion, the picture blocks, motion vectors of the picture blocks in thefirst picture region and an overall motion vector being coded, theoverall motion vector being used to describe a shift of the firstpicture region in comparison to the first picture region in at least oneof a previous predecessor picture and a subsequent successor picture;and said processor carrying out a decoding of the compressed picture byusing the overall motion vector for decoding at least some of thepicture blocks in the second picture region.
 14. The configurationaccording to claim 13, wherein said processor is configured such thatthe overall motion vector is determined from motion vectors of pictureblocks in the first picture region.
 15. The configuration according toclaim 13, wherein said processor is configured such that the overallmotion vector is determined by forming a mean value of motion vectors ofpicture blocks in the first picture region.
 16. The configurationaccording to claim 13, wherein said processor is configured such thatthe overall motion vector is determined from motion vectors of givenpicture blocks in the first picture region, the given picture blocksbeing located substantially at an edge of the first picture region.